Spin recovery
Early spinning was done from a stall with the throttle closed. Only later would one spin by pulling hard into the buffet in a steep turn or loop when it could flick any way into a partial control spin.
Quite a few JPs were lost spinning.
Incidentally the same student was flying with another instructor when the solution to non recovery was found. They spun down from 25000 taking all the appropriate actions and were still spinning at 3000. As the instructor tried to get in a Mayday call to say the were ejecting it finally recovered. A/C was taken to Hunting who fitted a spin chute and had to use it on the first test flight. Problem was assymetric fuel in tips.